Ollie Willis, 65, brought two of her teenage grandchildren along to a cookout in Roxbury Saturday afternoon. She wanted them to visit the booth where city workers were signing up kids for summer camps and jobs.

“I want to keep them off the street, keep them from getting into trouble or getting into drugs,” she said. “There's a lot of violence around here.”

Roxbury has seen a steep increase in violent crime this year. By late June of last year, District B-2 — which includes Roxbury and part of Dorchester — had seen six homicides, said Officer Catherine Shea. This year, there have been 12.

On Friday evening, a 19-year-old man was shot on Fenno Street and Walnut Avenue, just a block or so away from where the cookout was held. He survived, and police have apprehended two suspects.

Saturday’s cookout was the fourth in a series of events meant to connect children to summer opportunities to prevent neighborhood violence. Throughout the day, city officials and volunteers knocked on about 250 doors, manned the booth, and talked to residents of the Warren Gardens housing cooperative, encouraging them to keep their children occupied.

Earlier in June, similar events were held at the St. Joseph’s and Charlame I and II housing cooperatives in Roxbury, where 67 young people signed up to receive applications for summer camps and jobs.

A few dozen Warren Gardens residents came to the cookout; they said they wanted their children to do something productive for the summer — and to stay off the streets, which they said have become increasingly dangerous.

“I don’t want him bored and doing silly things on the street.”

Christina Campbell, Signed her 13-year-old son up for camp

Christina Campbell, 43, who recently moved to Roxbury from Connecticut, signed up her 13-year-old son for camp to give his summer some structure.

“I don’t want him bored and doing silly things on the street,” she said. “You know what they say, idle time is the devil’s playground.”

Youngsters who spend their summers at camp or in a job are connected with mentors and learn skills — like cooperation, problem-solving, and sportsmanship — which equip them for success, said Barbara Ferrer, executive director of the Boston Public Health Commission. They also tend to be better prepared for the next academic year, she said.

The door-knocking and cookouts also help the city gauge neighborhood needs one-on-one, said Mayor Thomas M. Menino, who stopped by in the early afternoon. He expressed hope that keeping young people busy would ultimately curb crime. The police cannot do it alone, he said.

Dot Joyce, a spokewoman for Menino who joined in on the door knocking Saturday morning, said people seemed grateful to talk to city officials about their fears and concerns, especially after Friday’s shooting.

“After an incident like that, people want someone to talk to,” she said. “One woman was so happy just to talk to us. We didn’t walk away or leave them without anyone.”

On Monday, state and city officials will meet at the Shelburne Community Center in Roxbury to announce more initiatives to prevent gun violence and ask community leaders and residents for additional input.

The meeting will be attended by Ferrer and, among others, State Representatives Carlos Henriquez and Russell Holmes, and Boston Police Chief Daniel Linskey.

Earlier Saturday morning, Naomi Crumb, a Warren Gardens resident, knocked on about a dozen doors as a volunteer.

She said she hoped all parents and their children in the complex would see that summer opportunities really do exist.

“This is a very peaceful, clean area, and a good place to raise children,” she said. “I just wish the violence would stop.”